A pressurized joule heating apparatus

Abstract

The application discloses a pressurized joule heat equipment, which adopts a modular three-layer graphite sleeve structure, the outermost layer is a fixed support outer sleeve, the inner layer is designed as a replaceable multi-layer sleeve combined with a graphite sheet group, is suitable for sample sizes in a variety of inner diameter ranges, avoids pollution of the core heating area caused by material adhesion, penetration or reaction through a physical isolation and replacement mechanism, and significantly reduces the loss cost of high-value graphite consumables; meanwhile, the internal temperature of the heating material is accurately detected through an infrared temperature measurement probe with an oblique angle of incidence, the temperature measurement deviation caused by the graphite wall thickness is bypassed by using the penetration and angle optimization of the infrared signal, and real material temperature field data are directly obtained; in the heat management aspect, a straight-through gas cooling channel is innovatively integrated, the gas inlet is directly extended to the heating area, directional forced convection and phase change heat absorption are realized by injecting inert gas or liquid nitrogen, and the material cooling efficiency is shortened from the natural heat dissipation of 24 hours.

Description

Technical Field

[0001] This invention belongs to the field of Joule heating equipment, and specifically relates to a pressurized Joule heating device. Background Technology

[0002] Functionalized nanomaterials can improve catalyst efficiency, reduce the cost and conversion efficiency of hydrogen energy, enhance the efficiency and lifespan of fuel cells, reduce precious metal consumption, and improve battery charge / discharge efficiency and safety performance, playing a revolutionary role in scientific research, industry, medicine, and energy. For example, ten years ago, mobile phone batteries frequently experienced combustion and explosion accidents. With the progress in research on functionalized nanomaterials in battery positive and negative electrode materials, combustion and explosion accidents in low-power batteries in mobile phones are now rare. The frequent combustion and explosion accidents in electric vehicles are actually caused by the instability of positive and negative electrode materials in high-power batteries. Researching and developing more stable and efficient functionalized nanomaterials is a feasible way to solve such problems. High-temperature thermal shock technology can prepare high-performance functionalized nanomaterials, leading the international research boom in the ultra-fast synthesis of new materials.

[0003] In existing technologies, high-temperature thermal shock devices mainly consist of four parts: a DC power supply, a heating reaction chamber, a thermometer, and a vacuum pump. Specifically, the sample material is connected to copper sheets via conductive silver paste and fixed to a glass support. The copper sheets at both ends of the sample are connected to the DC power supply. Turning on the power supply initiates a high-temperature thermal shock. The thermometer is used to measure and calculate the sample temperature; generally, low-temperature thermocouples are used, infrared thermometers are used for high temperatures, and color temperature meters are used for even higher temperatures.

[0004] Traditional Joule heating pressurization equipment suffers from three key problems: insufficient temperature measurement accuracy, easy contamination and wear of the graphite sleeve, and low cooling efficiency. First, the thermometer used in the equipment is placed horizontally outside the graphite sleeve, only detecting the temperature of the outermost layer of graphite. Due to the thick graphite wall (lagging heat conduction between inner and outer layers), a significant temperature difference occurs between the inside and outside, failing to accurately reflect the true heating temperature of the internal material and affecting experimental parameter control. Second, the single-layer graphite sleeve is prone to reaction with or contamination by the internal material during high-temperature pressurization (such as material residue and carbide formation), leading to rapid deterioration and scrapping of the sleeve. As a high-value consumable, frequent replacement of the graphite sleeve significantly increases costs. Finally, the equipment lacks an efficient cooling design, relying on natural heat dissipation, resulting in cooling times of up to a day, severely restricting experimental cycle efficiency. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a pressurized Joule heating device that employs a modular three-layer graphite sleeve structure. The outermost layer is a fixed support outer sleeve, while the inner layer is designed as a replaceable multi-layer sleeve combined with graphite sheets, suitable for sample sizes with various inner diameters. Through physical isolation and replacement mechanisms, it avoids material adhesion, penetration, or reaction that could contaminate the core heating zone, significantly reducing the cost of high-value graphite consumables. Simultaneously, it uses an angled infrared temperature probe to accurately detect the temperature of the heating material, utilizing the penetrability and angle optimization of infrared signals to bypass temperature measurement deviations caused by graphite wall thickness, directly obtaining the material's true temperature field data. In terms of thermal management, it innovatively integrates a direct-flow air-cooling channel, extending the air inlet directly to the heating zone. By injecting inert gas or liquid nitrogen, it achieves directional forced convection and phase change heat absorption, reducing the material cooling efficiency from the 24-hour range of natural heat dissipation.

[0006] Specifically, including: Vacuum cavity; A graphite sleeve disposed inside the vacuum chamber; the graphite sleeve has a vertical through hole; The upper and lower graphite sheets are slidably disposed in the vertical through hole, and the graphite sleeve and the graphite sheets together form a sample carrying space; The power supply system includes an upper conductive bracket connected to the upper graphite sheet and a lower conductive bracket connected to the lower graphite sheet. The upper and lower conductive brackets are connected to the positive and negative terminals of an external power supply. The upper and lower conductive brackets are each independently connected to a driving device to drive the graphite sheet to move up and down in the vertical through hole through the conductive brackets. An infrared thermometer, placed inside a vacuum chamber, is used to collect the temperature of the graphite sheet. The cooling nozzle, located inside the vacuum chamber, is used to spray cooling gas into the vertical through-hole.

[0007] The present invention also provides a pressurized Joule heating device, comprising: Vacuum cavity; A graphite sleeve disposed inside the vacuum chamber; the graphite sleeve has a vertical through hole; An upper graphite sheet is slidably disposed in the vertical through hole and a lower graphite sheet is fixedly installed at the bottom of the vertical through hole. The graphite sleeve and the graphite sheet together form a sample carrying space. The power supply system includes an upper conductive bracket connected to the upper graphite sheet and a lower conductive bracket connected to the lower graphite sheet. The upper and lower conductive brackets are connected to the positive and negative terminals of an external power supply. The upper conductive bracket is connected to a driving device to drive the graphite sheet to move up and down in the vertical through hole through the conductive bracket. An infrared thermometer, placed inside a vacuum chamber, is used to collect the temperature of the graphite sheet. The cooling nozzle, located inside the vacuum chamber, is used to spray cooling gas into the vertical through-hole.

[0008] Furthermore, the upper and lower electrodes are graphite electrodes. The upper and lower electrodes can be replaced with graphite electrodes of different diameters, thereby adapting to graphite sheets and graphite sleeves of different diameters.

[0009] Furthermore, the driving device is mechanically pressure driven, pneumatically driven, or hydraulically driven.

[0010] Furthermore, the nozzle has a bent angle structure.

[0011] This pressurized Joule heating device can process conductive samples by directly heating them using Joule heating. It can also process non-conductive samples by indirectly heating them with an external cylindrical graphite core or by generating plasma with a large current from both top and bottom to directly break down the material, thereby improving its properties. The material type can be powder or cylindrical bulk material.

[0012] The advantages of this invention are: (1) Utilize the penetration and angle optimization of infrared signals to bypass the temperature measurement deviation caused by the thickness of the graphite wall and obtain the true temperature field data of the material; (2) A modular multi-layer graphite sleeve structure is adopted. The outermost layer is a fixed support and heat insulation outer sleeve, and the inner layer is designed as a replaceable multi-layer sleeve and graphite sheet combination, which significantly reduces the consumption cost of high-value graphite consumables. (3) Using a cooling nozzle significantly reduces the rate at which the sample cools down after the reaction is complete. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of Example 1; Figure 2 This is a schematic diagram of the structure of Example 2; Explanation of reference numerals: 0, Vacuum chamber; 1, Graphite sleeve; 1-1, Upper graphite sheet; 1-2, Lower graphite sheet; 2, Infrared thermometer; 3-1, Upper electrode; 3-2, Lower electrode; 3-3, Support; 4, Nozzle. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0015] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0016] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0017] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] According to a preferred embodiment of the present invention, the sample is conductive. In some embodiments, the sample may also be non-conductive, and its properties can be improved by indirectly heating it with an external cylindrical graphite or by generating plasma with the same current from both the top and bottom to directly break down the material itself.

[0022] Furthermore, the upper and lower electrodes are graphite electrodes.

[0023] Furthermore, the upper and lower electrodes can be replaced with graphite electrodes of different diameters.

[0024] Example 1: Double-sliding graphite sheet device Vacuum chamber: Connected to a vacuum pump to maintain a pressure ≤5×10⁻³ Pa.

[0025] Graphite sleeve: It consists of 3 sleeves: the outermost sleeve (outer diameter 200 mm), the middle sleeve (outer diameter 150 mm), and the inner sleeve (inner diameter 50 mm).

[0026] Graphite sheets and electrodes: The upper and lower graphite sheets are 50 mm in diameter and are driven to slide by a stepper motor with a spacing adjustment accuracy of ±0.1 mm; the electrodes are made of isostatic graphite (50 mm in diameter) and are fixed to the hydraulic drive bracket by locking buckles.

[0027] Pressurization and temperature measurement: The hydraulic system pressurization range is 10-150 MPa, and the infrared thermometer is installed at a 15° tilt angle with a temperature measurement range of 150-3000℃.

[0028] Cooling nozzle: Made of 316 stainless steel, with an irregular bend and a nozzle diameter of 2 mm. Liquid nitrogen is introduced to quench the sample.

[0029] Core component assembly: The lower electrode is detachably connected to the lower bracket via locking clips to ensure reliable electrical connection and stable position.

[0030] like Figure 1 As shown, place the lower graphite sheet above the lower electrode so that it is in close contact with the lower electrode.

[0031] The inner sleeve is placed over the lower graphite sheet and lower electrode assembly to ensure accurate positioning.

[0032] Place the upper graphite sheet into the inner sleeve, ensuring it is in close contact with the inner wall of the inner sleeve and can move axially.

[0033] The upper electrode is detachably connected to the upper bracket via a locking buckle and placed above the inner sleeve, in contact with the upper graphite sheet. At the same time, the relative positions of the upper and lower electrodes are adjusted to meet the electrical performance requirements.

[0034] Graphite sleeve assembly installation: The middle sleeve and the outermost sleeve are sequentially placed over the assembled core component. The outermost sleeve covers the middle sleeve and the power supply system to form an insulation structure.

[0035] Conduct preliminary power-on tests to check the conductivity of the electrodes, the accuracy of the infrared thermometer's temperature measurement, the smoothness of the sliding of the upper and lower graphite sheets, and the working status of the nozzle, and make necessary adjustments based on the test results.

[0036] Based on the sample characteristics and process requirements, set the temperature monitoring parameters of the infrared thermometer, the operating parameters of the nozzle (such as flow rate, pressure, etc.), and the current and voltage parameters of the power supply system.

[0037] Place the powdered conductive metal sample between the upper and lower graphite sheets, and adjust their positions to form a sample holding space of appropriate volume.

[0038] When the equipment is started, the power supply system energizes the sample by contacting the upper and lower graphite sheets with the upper and lower electrodes, respectively, causing Joule heating. Simultaneously, the upper and lower electrodes can move axially along the support, applying pressure to the sample via hydraulic pressure.

[0039] The infrared thermometer monitors the temperature of the sample or electrode in real time and feeds the data back to the control system. If the temperature exceeds the set range, the control system can adjust the power supply parameters or activate the nozzle for cooling.

[0040] After the reaction is complete, the nozzle sprays liquid nitrogen, the cooling medium, into the sample container space according to the set parameters to control the cooling rate of the sample.

[0041] Example 2: Equipment for fixing a graphite sheet like Figure 2 As shown, this embodiment provides a pressurized Joule heating device, specifically including a graphite sleeve assembly nested inside a vacuum chamber 0. The graphite sleeve assembly is composed of coaxial sleeves, including an outermost sleeve, at least one middle sleeve, and an inner sleeve that are sequentially fitted from the outside in. The outermost sleeve covers the middle sleeve and the power supply system to form a heat insulation structure. The middle sleeve and the inner sleeve are replaceable. An upper graphite sheet and a fixed lower graphite sheet are slidably disposed within the inner sleeve. The upper graphite sheet is in close contact with the inner wall of the inner sleeve and moves along its axial direction. The graphite sleeve and the graphite sheet together form an adjustable volume sample accommodating space. The lower graphite sheet is fixed, and the upper graphite sheet is driven by a motor to slide (stroke 0-30 mm).

[0042] The power supply system includes an upper electrode that is detachably connected to the upper support via a locking buckle, and a lower electrode that is detachably connected to the lower support via a locking buckle. The upper electrode and the lower electrode are respectively in contact with the upper graphite sheet and the lower graphite sheet to conduct electricity, and the upper and lower electrodes can move along the axial direction of the support to apply pressure to the sample. Infrared thermometers installed at an angle of 15-75 degrees; and the nozzle located at the top of the inner sleeve.

[0043] Non-conductive sample processing: After removing the graphite sheet, install a cylindrical graphite heating element (5 mm wall thickness) and indirectly heat the ceramic sample to 1600℃ through external electrodes.

[0044] Pneumatic pressurization: The hydraulic module is replaced with a pneumatic cylinder, which provides a pressure of 0.1-10 MPa and is suitable for low-pressure sintering of brittle materials.

[0045] The lower electrode is fixedly connected to the lower bracket, and then the lower graphite sheet is fixedly installed at the bottom of the inner sleeve.

[0046] The inner sleeve is placed over the lower electrode and lower graphite sheet assembly.

[0047] The upper graphite sheet is placed inside the inner sleeve, so that it is in close contact with the inner wall of the inner sleeve and can move axially.

[0048] The upper electrode is detachably connected to the upper bracket via a locking buckle and placed above the inner sleeve, in contact with the upper graphite sheet.

[0049] Graphite sleeve assembly installation Similar to Example 1, two middle sleeves and an outermost sleeve are installed sequentially to form an insulation structure. The innermost graphite sleeve has an inner diameter of 20mm.

[0050] Infrared thermometer and nozzle installation Install and test the infrared thermometer, and install the nozzle with a bent angle structure to ensure it works properly.

[0051] Check the status of each component and set parameters for the infrared thermometer, nozzle, power supply system, etc.

[0052] A non-conductive sample is placed between a lower graphite sheet and an upper graphite sheet; the material itself is directly broken down by indirect heating through an external cylindrical graphite sheet or by generating plasma with the same large current from both the upper and lower sheets.

[0053] When the equipment is started, the power supply system energizes the upper and lower electrodes to contact the upper and lower graphite sheets, respectively, to heat the sample. The upper electrode can move along the axial direction of the support, applying pressure to the sample via a pneumatic cylinder.

[0054] An infrared thermometer monitors the temperature in real time, and the nozzle sprays cooling medium according to the set parameters.

[0055] Operators monitor the equipment's operating status and promptly handle any abnormal situations.

[0056] The above embodiments detail the structure, features, and effects of the present invention. The above descriptions are merely preferred embodiments of the present invention. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent variations, that do not exceed the scope covered by the specification should be within the protection scope of the present invention.

Claims

1. A pressurized Joule heating device, characterized in that, include: Vacuum cavity; A graphite sleeve disposed inside the vacuum chamber; the graphite sleeve has a vertical through hole; The upper and lower graphite sheets are slidably disposed in the vertical through hole, and the graphite sleeve and the graphite sheets together form a sample carrying space; The power supply system includes an upper conductive bracket connected to the upper graphite sheet and a lower conductive bracket connected to the lower graphite sheet. The upper and lower conductive brackets are connected to the positive and negative terminals of an external power supply. The upper and lower conductive brackets are each independently connected to a driving device to drive the graphite sheet to move up and down in the vertical through hole through the conductive brackets. An infrared thermometer, installed inside a vacuum chamber, is used to collect the temperature of the graphite sheet. The cooling nozzle, located inside the vacuum chamber, is used to spray cooling gas into the vertical through-hole.

2. A pressurized Joule heating device, characterized in that, include: Vacuum cavity; A graphite sleeve disposed inside the vacuum chamber; the graphite sleeve has a vertical through hole; An upper graphite sheet is slidably disposed in the vertical through hole and a lower graphite sheet is fixedly installed at the bottom of the vertical through hole. The graphite sleeve and the graphite sheet together form a sample carrying space. The power supply system includes an upper conductive bracket connected to the upper graphite sheet and a lower conductive bracket connected to the lower graphite sheet. The upper and lower conductive brackets are connected to the positive and negative terminals of an external power supply. The upper conductive bracket is connected to a driving device to drive the graphite sheet to move up and down in the vertical through hole through the conductive bracket. An infrared thermometer, placed inside a vacuum chamber, is used to collect the temperature of the graphite sheet. The cooling nozzle, located inside the vacuum chamber, is used to spray cooling gas into the vertical through-hole.

3. The pressurized Joule heating device according to claim 1 or 2, characterized in that, The power supply system is energized by contacting the upper and lower graphite sheets through the upper and lower electrodes, respectively. The upper and lower electrodes are graphite electrodes.

4. The pressurized Joule heating device according to claim 1 or 2, characterized in that, The driving device is mechanically pressure driven, pneumatically driven, or hydraulically driven.

5. The pressurized Joule heating device according to claim 1 or 3, characterized in that, The nozzle has a bent angle structure.

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